I've noticed that when I go up in the radius in CR sharpen, the image looks painterly. I would like to know what's the reason or if I'm doing something wrong.I've attached a comparison between acr and photoshop sharpening, left acr amount 100 radius 3 detail 100 mask 0. Right unsharp mask amount 100 radius 3.

Even if I usually never go beyond 1 in capture sharpening this effect annoys me because I can't keep from thinking it's doing the same thing in small amounts.

The fact is that there is not a 1:1 relationship between ACR sharpening (that works on luminance data in gamma 1.0 space) and USM that is working on a gamma encoded working space. Therefore you can't use the same settings and expect the same result.

Higher radius is used for low frequency image data, something YOUR image ain't. Depending on the source file (you don't bother to mention that camera or capture size) somewhere in the .7-1.0 would be the max radius that image needs. Putting the radius at 3 is simply miss-sharpening the image (which is why it looks like that). I would also question the amount of 100 (which again has _NO_bearing on the amount in USM) of being too high even if you brought the radius down.

Look, any tool in Camera Raw/Lightroom (or Photoshop for that matter) is capable of screwing up your image...seriously, if it hurts the image to do that, don't do that...

Image was for demostration purposes only, I never use that settings, this image was a 100% crop from 1dsmII, now I use the 1dsmIII and usually don't go over 50 in amount.

Anyway thanks for explanations, I understand that acr sharpen is just designed for capture sharpening and it just have to do so, anyway I cannot imagine what kind of input resolution woiuld be need in order to use radius 3, if it doesn't exist such device maybe would be better to not let the slider go so high.

I cannot imagine what kind of input resolution woiuld be need in order to use radius 3, if it doesn't exist such device maybe would be better to not let the slider go so high.[a href=\"index.php?act=findpost&pid=209584\"][{POST_SNAPBACK}][/a]

Low frequency images (soft edged or images with little edge detail) benefit–particularly in combination with an edge mask. I often use a higher radius (1.5-2.5) when sharpening certain portraits and using an edge mask between 60-70.

As for why it goes so high...for the same reason Amount goes to 150 and Brightness goes to 150. Sometimes you need more...